75 lines
1.8 KiB
D
75 lines
1.8 KiB
D
// Copyright Brian Schott (Hackerpilot) 2014.
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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module analysis.length_subtraction;
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import std.stdio;
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import std.d.ast;
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import std.d.lexer;
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import analysis.base;
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import analysis.helpers;
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/**
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* Checks for subtraction from a .length property. This is usually a bug.
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*/
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class LengthSubtractionCheck : BaseAnalyzer
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{
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alias visit = BaseAnalyzer.visit;
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this(string fileName)
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{
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super(fileName);
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}
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override void visit(const AddExpression addExpression)
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{
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if (addExpression.operator == tok!"-")
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{
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UnaryExpression l = cast(UnaryExpression) addExpression.left;
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UnaryExpression r = cast(UnaryExpression) addExpression.right;
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if (l is null || r is null)
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{
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// stderr.writeln(__FILE__, " ", __LINE__);
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goto end;
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}
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if (r.primaryExpression is null || r.primaryExpression.primary.type != tok!"intLiteral")
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{
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// stderr.writeln(__FILE__, " ", __LINE__);
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goto end;
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}
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if (l.identifierOrTemplateInstance is null
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|| l.identifierOrTemplateInstance.identifier.text != "length")
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{
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// stderr.writeln(__FILE__, " ", __LINE__);
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goto end;
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}
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const(Token) token = l.identifierOrTemplateInstance.identifier;
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addErrorMessage(token.line, token.column,
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"dscanner.suspicious.length_subtraction",
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"Avoid subtracting from '.length' as it may be unsigned.");
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}
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end:
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addExpression.accept(this);
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}
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}
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unittest
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{
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import analysis.config;
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StaticAnalysisConfig sac;
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sac.length_subtraction_check = true;
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assertAnalyzerWarnings(q{
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void testSizeT()
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{
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if (i < a.length - 1) // [warn]: Avoid subtracting from '.length' as it may be unsigned.
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writeln("something");
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}
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}c, sac);
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stderr.writeln("Unittest for IfElseSameCheck passed.");
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}
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